FatePurgatory
by TheDevilIsInDetail
Summary: To attain salvation through suffering is the meaning of purgatory. Because all debt must be paid in order to be free. Kotomine Kai is an Executor. Humanity's weapon against the damned. And this world... is his purgatory. Nasuverse/DxD Crossover. Dark AU.
1. Prologue

**Fate/Purgatory**

 **Disclaimer: The original story, elements, and characters of High School DxD and of Nasuverse belongs to Ishibumi Ichiei and Kinoko Nasu respectively. Any other elements and characters that may appeared in this fic belongs to their respective owners. I only own this plot and any original characters within this story.**

 **AN: This story has been in my mind for quite some time so I decided to write it down. One thing I know, it took a lot of paper to turn what you think into a legible piece of writing. Also, I'm going to say in advance for any grammar mistakes. My English is not that good since I'm not British, American, or native to any country that speak English. Oh, and for all flamers that may appeared later on, burnt in Hell.**

– **Fate/Purgatory–**

 **Prologue**

 _ **Shinto district of Fuyuki City**_

 _ **Ten Years Ago**_

 _Fire._

 _There's nothing around me but fire consuming everything, anything, on its path._

 _How long has it been? An hour? Two? It felt like it's been hours for me. I can't run anymore. I can't even feel my legs and the heat is just too much for me. I can see burnt marks on my arms and feel burning sensation in my lungs, but I'm just too tired to bring myself to care. But I can't… no, I must not stop. No matter what happens, I must survive. And then I saw it, just past the wall of thin smoke and fire, part of the city that wasn't touched by the fire. "_ Succeed _," I thought. Despite the injuries and how tired I am, I managed to survive. Safety was just a few steps in front of me. But then, as if fate trying to mock me, the cursed mud suddenly flooded my way, burning my only path to safety and my last hope._

"Useless," _I thought as I stared blankly at the wall of wild fire in front of me. Everything is for naught. No matter how close I am, safety feels very far now with that accursed flame on my way. This is no different from when I started running. Hopeless._

 _The mud finally got me on its grasp as I fell on my knees in the midst of flames and ruins, but I just don't care anymore. Strange, it didn't burn me like I thought it would. Suddenly I felt excruciating amount of pain accompanied with sudden feeling of intrusion as dark thoughts started to fill my head._

 _ **The starting penalty is five.**_

 _ **Life penalty, Body penalty, Freedom penalty, Fame penalty, Fortune penalty.**_

 _ **Give the penalty that extends so much punishment, mud, darkness, and malice.**_

 _ **Elimination of human rights by castration, exile, and execution. Torture and sadism inflicted upon the human body through digestion. Denial by the consensus of the colony that eliminates all honor.**_

 _ **DIE.**_

 _ **Scorn from judgment and selfishness that takes away men's fortune.**_

 _ **Death penalty, penal penalty, imprisonment, custody, fine penalty, crime from a grudge, crime from self-interest, unconscious crime, self-conscious crime, civil war, inducement, false statement, theft, robbery, kidnap, suicide, rape, arson, bombing, violation, negligent homicide, mass violence, death at work, overconfident accident.**_

 _ **DIE. DIE. DIE.**_

 _ **Misdiagnosis, concealment, violation for benefit, violation for self-protection, violation for love, violation for respect, selfish. Stealing, fraudulent, fraud, concealment, murder, theft, crime, personal grudge, attack, attack, attack, dirty, dirty, dirty, YOU are dirty, atone, atone for your crimes, atone for the crimes of others, atone for every crime, every victim, atone for everything.**_

 _ **The world you know is ruled by something not human. Know the conscience to reform crimes.**_

 _ **DIE. DIE. DIE. DIE. DIE.**_

 _ **Know the penalty to reform crimes. People's kindness is here. There is so much it cannot be noticed. Know the violence to hide crimes. Know the power to hide crimes. People's malignance is here. It is so rare that it is noticed. A hundred acts of kindness and one act of malignance. Malignance shines bright to keep the balance and exists as a great EVIL to compete with the masses of kindness. The starting penalty is five.**_

 _ **DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE.**_

 _ **No one is innocent. Everyone is guilty. Everyone has committed crimes. Bathe in the sins of humanity. Know the pain of their victims. Feel their terror. Feel their despair. Atone. Atone for the crimes of mankind. Atone through death. Kill. Be killed. Atone by death. Atone. DIE.**_

 _ **DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE.**_

 _ **DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE.**_

 _ **DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE.**_

 _ **DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE. DIE.**_

 _ **DIE. DIE. DIE. DIE. DIE. DIE. DIE.**_

 _I couldn't breathe and my body screamed in agony. I couldn't think as my mind was filled with memories; memories of every sins committed by humanity; I can feel their wrath, their greed, their lust, their hunger and thirst for more; I could feel the scream of anguish from every victim resulted from those sins and it brought nothing but pain, hellish pain. I opened my mouth in silent scream as I tried to forget those memories, but I couldn't. Something inside me forced me to watch it, to feel it, to embrace it._

 _I couldn't stand it. All those sins, all those greed, wrath, hunger. All those hatred. I don't want them. I want them gone. I don't want to feel them. Even death would be better than this. I want them gone. I want all of this GONE!_

 _"_ …Wish… _"_

 _Despite the agony I was in, I could hear the voice though only barely. The voice itself was no louder than a whisper._

 _"_...make…wish… _"_

 _That voice again. Why? Why should I? Does wish something will free from this pain?_

 _"_ …Yes… Make a wish… It will…free…you… _"_

 _The pain I felt is still going on, increased even. My wish is definitely clear. To be free. Free from all of this, especially this… hell. I tried to say my wish, but the agony prevent me from doing so and my voice wouldn't come out. When I managed to say my wish, it was barely more than a dying breath._

 _"…I…wish…to…live…free…from…this…hell…"_

 _"_ …yes… _" the voice responded to my wish. There was a hint of underlying malice at its tone but I didn't notice it. Then the world glowed as bright blue flame engulfed it and there was a surge of… something as the flame burned through the mud. Then suddenly, all those feelings stopped as if the fire cleansed them too. The next thing I knew was my view slowly blurred and darkened, but the image of blue flame burning brightly never truly escape me. Awe and content was all I felt left as darkness engulfed me completely._

* * *

As if his internal alarm was set off, Kotomine Kai awoke as his eyes were snapped open at all sudden, revealing the cold blue irises beneath them. He straighten up from his seat and took a look around. A flash of confusion appeared on his eyes as he observed his surroundings before he remembered where he was now. He was on an airplane heading to Japan to accomplish a mission given by the order of the Church.

He took a deep breath to calm his mind as he remembered just what he had dreamed of. It has been a long time since the last that memory haunted his dreams. He thought he had gotten over it just like many times before when he no longer dreamed of it, but then the memory visited him again as if to remind him he could not escape what made him who he is now. He should've known better. That memory was his origin. His beginning. He has no memories of his life prior to that hellish night. He couldn't remember his former name, his real parents, whether he has siblings or not, his home, or even his own birthday. Whoever he was before, that boy was no longer exist. In his place, Kotomine Kai who was born in the sea of flame forever stood.

The last thing he remembered before he passed out was a scene of a city set ablaze in brilliant blue flame; an image he would carry to his death. When he finally woke up, he was laid in a bed in hospital hall and six months had passed since that fateful night.

Kai didn't know it at the time, but that night was what started his path in the world of supernatural. World where humans were prey for monsters hidden in darkness. Where only the strongest could survive and carry on with their lives.

Such was a cruel world Kotomine Kai dedicated himself into. Almost half of his life was spent in this world. In fact, he thrived in it. At the mere age of 17, he was already become a part of the notorious **Burial Agency** in addition to his status as a First-class **Executor** of the **Holy Church**. His hands were already stained with blood from hundreds or perhaps thousands of monsters he had slain, all for the sake of humanity. Wars, battles, deception, cruelty, and death had become an inseparable part of him, part of what made him into who he was now, part that he privately admitted to enjoy.

Having been involved in the supernatural world for so long, it was inevitable that Kai would find the normal world 'foreign.' A world where humans could live mostly peaceful and only need to worry for petty things was… unfathomable for him. Kai understood should he ever stepped into that world, he knew he would be lost immediately. He would have no purpose, no way to relate with the common folk. Peace was not something meant for him. He had been a sword for so long, and a sword was meant as a weapon, a tool used to kill, not some meaningless wall decoration. A sword has no place but in the battlefield.

Even amongst dark-siders of the Church, Kai has a reputation of a sword; cold, unfeeling, sharp, efficient. Something he found to be ironic as the description was the exact opposite of his element. His greatest weapon and just about one thing he truly mastered in the art of Magic.

Even so, Kai could not say that they were wrong about him. A sword was the correct analogue for him. He knew he had change quite a bit from the blank, apathetic kid he was when he joined here the first time, but in some aspect, he was still a sword just the same. And as a sword, he shall cut down the blight that stained this world as God has commanded him.

The cabin's speaker suddenly sprang up and announced that they would arrive at the airport shortly. The cabin suddenly filled with noises as passengers got up from their seat to prepare their luggage. Deciding to follow their example, he got up and took a simple duffle bag from the luggage rack before sitting back and looked out of the window as his mind went back to mission that was given to him.

* * *

 _His face was blank as ever, but a barely noticeable glint on his eyes betrayed that impassiveness, revealing the slight nostalgic feeling he has as he walked inside the room. It hasn't changed very much since the first time he entered through those very doors when he was only ten years old, specifically on the day he was officially inducted as an Executor of the Church. It was still plain as ever, barely furnished with just a few wooden book cases, a small fireplace, a desk, and several chairs within. Overall, the room gave the impression of antiquity and also dullness._

 _He shifted his gaze to the priest who sat behind the desk, busy typing using an antique typewriter. He was the very same man who welcomed him to this institution seven years ago, yet the man seemed not to age a day since that meeting._

 _The priest appeared to be a rather unassuming, though handsome, and youthful. Yet, his silvery hair, the scars that featured his otherwise appealing look, and the power behind the gaze of those blue eyes betrayed his true age and the untold amount of experiences he has. From his look alone, one could already discern him as someone who has been tempered by the harshness of life._

 _The priest garment he wore did not hide his well-defined physique. It wasn't a built of a professional athlete, however. Rather, it was a figure shaped for the sole purpose of fighting and killing. Built that is meant to be used._

 _"Hello Kai."_

 _Kai had opened his mouth and was about to greet him when the priest greeted him first all of sudden without even stopping from his work._

 _"Father Garule," Kai greeted him back, bowing slightly to show his respect. "Your senses are sharp as ever."_

 _The priest, Garule, chuckled in response. "Sharp?" he questioned rhetorically to his statement. "My senses now are no longer as sharp as it used to be, Kai. I can barely sense you entering the office anymore. Of course, the fact that your skill in concealing presence is improving also contributed a lot to it."_

 _Kai let out a slight smile at that. "That you can sense my presence from that far only shows that I am still a failure as an assassin, Father," he said lightly._

 _"That you are, my student," the older man agreed. "Worry not, however. You are first and foremost an Executor, the sword that carry out God's order. So long as you slay our enemies, your mission is completed flawlessly," he continued as he returned his attention to the typewriter._

 _For a few minutes, there are no other sounds in the office aside from the sound made by the typewriter as the priest working on a paper. When he was finished, he handed one of the folder on the table for Kai to read. The words atop of the folder made him raise a brow._

 _ **Venatione Veneficae.**_

 _"A witch hunt, Father?" he questioned. This wasn't the first time Kai was sent to one, but since a witch hunt was considered to be a low-priority mission, such mission was no longer made available to him ever since he was promoted into a First-class Executor._

 _"Correct," the older man nodded. "You remember of the fallen Holy Maiden?"_

 _"Asia Argento," Kai answered. "I was tasked to protect her during her time in Italy quite a while ago."_

 _"And how did that turn out?"_

 _"Mission was deemed a failure. She healed a Devil when she managed to slip past the watch who replaced me for the day. I returned in time to slay the Devil, but she was found guilty of heresy and thereby was excommunicated from the Church."_

 _"Good. You remembered your mistakes. I want you to know that we were lenient toward you for that failure since your previous record were flawless," said Garule. He then gave him the paper he typed previously. "This order comes from the top and cleared by Seraph Raguel himself."_

 _Kai accepted the paper and skimmed over it silently before putting it into the folder on his hand._

 _"If I may ask, Father?" he asked to which the older man signed him to continue. "There are no records of Asia Argento committing other heresy after she was excommunicated. Why gave the order, then?"_

 _"That is no longer the case," Garule replied. "Several weeks ago, our intel reported that she was recruited by the Fallen. It's in the dossier."_

 _Kai opened the folder and quickly found the damning evidence against her. "I see."_

 _"She cannot be allowed to join the forces of the Fallen. The Twilight Healing's capabilities enhanced with whatever breakthrough Azazel may create from his research on Sacred Gears will put us at disadvantage should another war break out. When another war breakout."_

 _Closing his eyes, Kai silently running through the scenario in his mind and he found no other choices to prevent the outcome. He opened his eyes and steeled his resolve as he knelt on one knee._

 _"I am the sword who shall bring forth judgement as God has commanded. Humanity's weapon against the damned. Point me to my enemies and retribution for blood of innocents shall be delivered."_

 _Garule smiled approvingly as he nodded. "Good. Go forth and deliver the vengeance, and may the Holy Father be with you."_

 _"Amen," he said the last word that decides his fate._

* * *

The sound of people walking out of the airplane snapped him back to reality. As he walked out of the plane, he looked up to the sky which somehow was no longer blue in his eyes. Rather, it was the dull monochrome of a forged iron sword.

Perhaps it was a sign that he would come to regret his decision later, but he had made his choice.

Asia Argento will die by his hand.


	2. Chapter 1

**Fate/Purgatory**

 **Disclaimer: The original story, elements, and characters of High School DxD and of Nasuverse belongs to Ishibumi Ichiei and Kinoko Nasu respectively. Any other elements and characters that may appeared in this fic belongs to their respective owners. I only own this plot and any original characters within this story.**

 **AN: Alright! Welcome to another chapter of Fate/Purgatory, guys! Thank you so much for wasting your time reading this story and especially for those who bothered to waste more time writing the reviews since it made my day. Oh yes, I got a review from some guess reader who thought my OC as Shirō. Please do not I mistake him for Emiya Shirō, especially when I don't particularly (read: really don't) like him. There is Emiya Shirō in this fic, after all I made DxD universe and the Nasuverse into one with rules that are more in line with Nasuverse rather than DxD, but I don't think I would give him a role, or even if I did, it would be a minor one or I would just arrange something to have him killed so all readers who thought my OC as Emiya Shirō would shut up. Right, onto the story then!**

– **Fate/Purgatory–**

 **Chapter 1**

Quaint was the word Kotomine Kai thought of when he saw the church his superior told him to head to. The building itself was neither too grand nor small, but the whole complex was actually quite large. The architecture was clearly old fashioned, but it has unexplainable pleasing quality that he had long associated with church buildings. The church was perhaps large enough to house 100 or so people. It was quite unusual for a church to be that big in Japan, especially since Christian is a very small minority in the country. He supposed there were enough Christian in the city to require a large enough church.

"Time for intel gathering, I guess," he muttered to himself and knocked on the door of the church.

The door was opened by a young nun, only a few years older than himself from her looks. The day was still quite early for any visitors, but she didn't seem to be surprised when she saw him.

"Father Kotomine, I presume?" She asked him.

"Indeed." Kai nodded in confirmation. "I'm guessing you're the caretaker of this church?"

The nun shook her head. "No, that would be Father Ayasegawa. I'm just one of the nuns tasked by the bishop of diocese to help him in taking care of this church."

"I see," he said, accepting the answer. "May I know your name, then?"

"My name is Okita Shizuka, Father," she bowed to which Kai replied in the same manner.

"Kotomine Kai. Pleased to meet you."

She nodded courteously then signed him to enter the church. "Father Ayasegawa is waiting for you. Please follow me."

The nun led him to a small room where a priest was praying in silence.

"Father Ayasegawa?" the nun called. "Father Kotomine is here to see you."

The priest finished his prayer quietly before stood up and turned to face them. He was a man in his fifties with hair that already greyed.

"Father Kotomine," he greeted with a bow. "My name is Ayasegawa Hiko. I have been informed by the Vatican that you would come. Welcome to Church of Misaki town."

"Glad to be here," Kai bowed back, but his expression was impassive as ever. "I presume you know why I'm here?"

He shook his head. "The Vatican did not disclose anything to me, but I was once an Executor years ago and I recognize the black cross on your left sleeve. I am aware of their reputation and what kind of mission they have, so I would imagine that you are here for someone."

"The fallen Holy Maiden, Asia Argento," Kai replied in affirmation. "She was reported to be somewhere in Kuō town from our intel."

"I see," he said solemnly, though he couldn't hide a hint of sadness behind his tone. "I met her once when I was stationed in Italy. She was a kind girl, one who was truly pure-hearted. A rarity in this world influenced by darkness."

"It is a shame," Kai agreed in neutral tone. "But I have my order. The higher ups said that you were responsible for keeping eyes on the Kuō town due to possible Devils presence there. Can you confirm her presence in the town?"

The elder man nodded in affirmation. "Yes. Sister Okita here reported to me that she saw her walking around the town, asking for the location of the abandoned church there. She also confirmed the presence of three low-class Fallen Angels along with fifty or so rogue Exorcists stationed at the mentioned church."

Kai turned to look at the nun who answered his questioning glance with a firm nod. "I see. What about the Devils? Can you confirm their presence in town?" he asked.

Father Ayasegawa looked nervous when he asked this, as did the young nun. They glanced at each other for a moment before the old priest spoke, "Yes, but their identity that makes it a problem."

Kai didn't react at all to that words. Bad news is just another day at the office for him, so he simply signed them to continue.

The elder priest handed him a folder instead of replying. He silently opened it and read the content before a small frown appeared on his face. "I see. That's problematic," his voice betrayed no emotion. Kai closed his eyes for a moment, silently contemplating his next move. Deciding that further consideration is needed in the light of information he had received, he requested to stay in the church for the night, which they granted. He was then led by the young nun into a room within the complex.

"This is your room, Father," sister Okita told him, showing him a spare guest room.

"Thank you for your hospitality, sister," Kai bowed to her in a polite grateful manner though neither his face nor his voice gave anything but impassiveness.

"It's my pleasure to help you, Father," she said politely, though Kai could tell that she was actually nervous behind that polite facade. "If you need anything more, please don't hesitate to ask me or any of the nun. We will be happy to help you." And with that, she left him to his rest.

Silently closing the door behind him, Kai changed his travelling outfit into a more comfortable casual one. He then lit up a candle before he took a seat in meditative position in silence. This mission had turned out to be more difficult than he thought. The objective itself was not that difficult, but completing it would be quite tricky considering what intel had reported about the town. Still, it could work to his advantage should he was able to handle it correctly. And whether it would go smoothly or not, it would not change the outcome.

* * *

For Hyōdō Issei, words such as "friends," "family," "comrades," or "close/precious person" meant nothing to him. For as long as he could remember, which stretched back to about seven years ago since he can't remember further than that thanks to his amnesia, he was always alone.

Oh, he was not an orphan as he still had his parents. It's just that they were… distant, to put it mildly. He wasn't blind. He could see that his parents were scared of him despite them trying their best to show that they loved him. He deducted that whatever had caused them to act like that, it was connected to the incident that caused him to lose his memories, judging from their happy family photographs that was taken before the incident. Whatever happened at the time, it made his parents terrified of him as if he was not human, as if he was a… _freak_.

His school life was equally secluded. He never had or made any friends throughout his years at school, not that he bother to try. His reputation as a delinquent who could, and had, sent an entire gang to the hospital by himself ensured that he was feared by other students, enough that they would sooner stay away rather than being his partner in a school project. His teachers were just as frightened of him. Ever since he put that one gang to the hospital, they avoided him like a plague and won't talk or even call him in the class unless it was absolutely necessary.

Simply put, loneliness _was_ the life of one Hyōdō Issei. That was all he ever knew, and he wasn't bothered about it. He'd never expect anything more or less in his life than what he already had and what he wanted. And companionship was never either one of them.

Today, Issei skipped the school again. He was strolling around the town as usual when he wasn't in the mood for school to clear his mind. One could say that this was his favorite past time since no one would bother him when he was strolling around. People were too busy minding their own business to pay attention to him, so he was free to do whatever he wanted. But then, he spotted one of those gang whom he had put into hospital once for trying to make him pay "taxes." Within _his_ own bloody territory. They were chatting up to a girl, a foreigner by the look of it, since she had long blonde hair that could be easily spotted even beneath the veil she wore. When he observed the girl, he noted that she seemed not to notice the lecherous face they made when they chatted to her and she even naively believed that they would help her so generously in her endeavor.

Now, normally he would silently follow them to make sure that the girl would be okay as he had no illusion of what their intention toward her, and his only reason to do so would be that he didn't like anyone not playing by _his_ rule within _his_ territory. It would have nothing significant to do with the girl. But somehow, this girl was different.

He could feel something in his gut gnawing at him to rip those gang apart for trying to harm the girl. For trying to harm what's _his_. This sudden bout of possessiveness confused him. He had never feel something like it before. Before, he was content with what he already had. Now, he felt the need to stake his claim for the girl.

He followed them from afar as he pondered upon this strange possessiveness until they finally arrived at an abandoned warehouse on the edge of town. The gang 'asked' the nun to have 'fun' with them, but apparently the nun finally realized of their intention and tried to run away to no avail as the members quickly trapped her, preventing her from escape. He was about to interfere when a literal, honest-to-god, bloody monster appeared all of sudden.

If you only looked at its face and upper torso, you would probably think it was a naked young woman who was abnormally tall, but the lower part of its body was what showed its true nature; it was gigantic and beastly with four legs, bearing heavy resemblance to some kind of mutated lion or something. However, Issei could care less about its appearance. What's intrigued him was how the aura it exuded affect him. It felt dark and inhuman, but most of all, utterly _inferior_. The sheer inferiority of it evoke a sense of disgust in him, made him sneer at the pure arrogance of this pathetic being that deluded itself as a superior existence.

Issei didn't even bat an eyelid when the monster wannabe slaughtered the gang members in bloody gore and eat their corpses. He was too busy pondering upon the pure amusement he felt when he watched the brutal massacre. He didn't feel utterly horrified, scared, or any of its equivalent as a human being supposed to be when they faced a monster. Instead, he's getting a sense of glee watching a so-called monster massacred a group of lowly scum like humans watching a predator eating its preys in a setup they made.

That thought made him paused a bit. Since when he no longer considered himself human? What had made him to think that he was superior compared to this… _beast_ in the first place? Weird did not even start to describe what he felt, but something inside him _knew_ it wasn't an arrogant claim. It was _fact_.

His mind was snapped from the train of thought when he heard the girl cried in fear and desperation when the wretched beast setting its sight upon her, its eyes gleamed in predatory hunger. The sight of it made his blood boiling. The nerve this lowly beast trying to claim what's _his_! For the first time after years of unfeeling coldness with bouts of passing bloodlust and glee that fade to nothing in mere moments, Issei truly felt something; pure, unadulterated rage accompanied by a murderous desire to utterly crush the beast.

Massive waves of monstrous red aura exuded from his body as Issei set his sight upon the beast who suddenly went still with looks of pure terror in its eyes when it spotted him. In mere blink of an eye, Issei was already upon it as he charged a punch with his left arm which was covered with red scaly gauntlet that he had no idea where it came from or when it even appeared. That single strike upon the beast annihilate it with explosion of menacing red aura, removing even the slightest trace of its existence along with its victims.

The world went silent for a moment after the beast was gone. Neither him, the nun, or even the world made a single sound to be heard. But then, he began to laugh. Laughter that held both joy and contempt, relief and bitterness over reality that almost sounded insane. For Issei, this was _the_ revelation. Now he understood why his parents feared him, giving the look that said he was anything but human. Why he simply couldn't relate to others around him. The answer had always been right in front of him all along. He was just too blind, too naïve to see it.

He's _not_ a human. He may looked like one, but within, he's anything but. What else that could explain his detachment, his power, his inhuman thirst for fight and blood, for total domination?

 _"Dragon…"_ something inside him whispered that word. Yes. That word fitted him down to the core. He may looked human, but he was a Dragon through and through.

Suddenly, a small, almost unnoticeable 'thud' and an admittedly cute yelp behind him caught his attention and he turned to see the young nun fell on her ass, her green eyes were all watery as her backside stinging from the pain.

Feeling a stare on her, the nun looked up to find her savior was looking straight at her with those fierce brown eyes that unnerved her greatly, but at the same time feels soothing. A contradiction which greatly confuse her. However, being the good, naïve nun she is, she decided to trust him, especially since he saved her from the monster that almost killed her.

"T-thank you for saving me, mister…?" her stutter faded at the end and her face scrunched in genuine confusion even though Issei could still pick up the fear on those innocent green eyes clear as day.

Issei opened his mouth to answer her unspoken question when suddenly his instinct flared up, warning him to immediately leave as he, somehow, sensed multiple presence approaching. None were threatening enough individually, but they were definitely stronger than the beast he'd just thrashed and with their number they have potential to be quite an annoyance. Especially with the nun around. He made up his mind instantly to follow his instinct and get clear of the area, bringing the nun with him. The thing is, with how quick the presence approaching the warehouse, he would not be able to, much as he hated the word, escape in time with the nun.

" **Use my power to…** _ **get away**_ **, boy.** " An inhuman voice whispered to him. Something about it giving off aura of great, and terrible, power. Something ancient beyond belief. Suddenly, the previous red aura exuded from him again as it spoke. It filled his head with a thousand questions, but now was not the time to get the answer. He got no alternative, so he decided to follow it, risky as it was. Instinctively, the image of his room appeared on his mind, the first place he had in mind to hide. He felt the read aura spiked and quickly grabbed the nun before the world gone in red haze. The last thing he saw before the world was completely drowned in red was a strange red circle with a crest on its center that gave off similar inhuman dark aura to the beast, unaware that as he gone, a pair of cold blue eyes had been observing them since the very beginning.

* * *

Kotomine Kai stood calmly on the roof of nearby house, observing the group of Devils who turned up at the warehouse, undoubtedly attracted by the aura of power the brown-haired boy gave off. He assessed each of them carefully, judging their potential threat based on the aura they exuded. Several among the group in particular caught his attention.

 _"Heiress of the Gremory and the Sitri. Sisters to the current Lucifer and Leviathan,"_ he mentally noted on the redheaded girl with bluish green eyes and another glasses-wearing girl with short black hair and violet eyes. His eyes then turned to the other Devils.

 _"Mostly consists of normal humans with rather high magical potential. Three Sacred Gear possessors: the boy with dragonic aura, the girl with long black hair and glasses, and lastly,"_ he paused a bit as he identified the last girl whom he was quite familiar with in the past. _"Izumi. Survivor of Valper Gallilei's Holy Sword Project. Possessor of a high-tier demonic-type, Sword Birth."_

 _"Two non-human reincarnated. A Fallen, or perhaps a Nephilim,"_ here he briefly looked at the girl with long ponytail before turning to a small, white-haired girl who looked like she belong to middle school or perhaps the elementary. _"And a Yōkai. Nekomata."_

Kai never moved from his place as he continued watching the Devils trying in vain to find the source of the previous power surge, or at least a trace or clue that allows them to identify the source and where they had gone.

Seemingly frustrated on the fruitless search, the Devils cleaned up the whole mess before leaving with their Magic Circle. Their leaving prompted Kai to approach the warehouse.

The Devils had done a fine job to clean the mess from wandering human eyes. Normal human eyes that is. For those who were experienced in the supernatural world, it's not even close to 'decent.' The slight leftover of magical signature would be easily picked up by anyone with enough experience.

He pondered upon the scene he had witnessed before the arrival of the Devils. The brown-haired boy exuded a powerful red aura unlike anything he'd ever felt before. So powerful that even the slight trace remained on the scene brought a chill on his spine as it screamed for absolute domination. Aura which has the distinct signature belongs to the Dragonkin.

Red. Domination. Dragon.

His normally passive blue eyes widened slightly as realization hit him. "The Welsh Dragon…" he whispered the words unconsciously.

There was no doubt about it. The brown-haired boy, whoever he was, had unknowingly become a major player in the world of supernatural. Just like his predecessors had been as the possessor of the infamous Red Dragon Emperor's Gauntlet. One of the thirteen Longinus which could kill even God.

This revelation brought a brief smile tugged on his lips. A smile which almost… _insane_. Filled with such a thirst to see blood spilled. To watch the world _burn_ till nothing left remained. Not even the ashes. His blue eyes was glowing with unquenchable fire that threatened to consume anything, _everything_.

Kai suddenly gritted his teeth and clenched his eyes shut, trying to suppress his more… extreme tendencies. This mission was too important and he cannot risk it, no matter what. Slowly but surely, he managed to assert complete control. With his passive expression back in place, Kai left the premise without further ado. No sense in staying longer that he needed to.

After all, he got a mission to complete.


End file.
